Heat 2 tablespoons oil in small shallow skillet.
Add potato; saute until tender.
Add onions; saute 2 minutes.
Remove vegetables from skillet; drain.
Beat eggs until frothy.
Add salt and pepper; mix well.
Heat 1 tablespoon oil in skillet.
Add half of egg mixture.
Using fork, poke holes in center of omelet to allow uncooked egg mixture to run under cooked omelet.
Cook 1 minute or until outside rim of omelet is formed.
Add half of potato and onion mixture.
Flip omelet; cook 1 minute or until omelet is set.
Repeat process with remaining egg and potato mixture.